The present invention relates to a device for smoothing and pressing down foil on bottles in labeling machines and is intended for the point of a blank of foil wrapped around the neck and head of a bottle with the point projecting at the head, and has a pot-like housing that can be moved axially against the head of the bottle and accommodates an elastic sponge structure.
In applying foil to bottles it is the smoothing of the projecting point of the blank of foil, that is wrapped especially against the face of the bottle head, that causes the most trouble because of the difficulty of uniformly distributing the resulting pile-up of material while completely covering the head and extensively protecting the sensitive foil. The difficulty increases with the increasing output of the labeling machine.
There has been no lack of attempts to solve the problem. German Patent No. 964 126 for example discloses a smoothing and pressing-down device that has a central component consisting of a resiliently supported die accommodated in a guide and an annular outer component consisting of a spiral ring in an axially stationary retainer that allows it to move only radially. Once the smoothing and pressing-down device drops onto the head of the bottle, the spiral ring rolls along the circumference of the bottle towards its axis while the die retreats. This presses the projecting and wrapped point of the foil blank against the head of the bottle and the sides of the blank against the bottle. Since the cross-section of the spiral ring does not allow it to match the curve of the bottle satisfactorily, the blank cannot be satisfactorily smoothed, and wrinkles in the vicinity of the bottle head. Furthermore, the foil is stressed to such an extent by the spiral ring as it travels axially over the bottle that damage to the foil must be taken into account.
Again, U.S. Pat. No. 2,297,720 discloses a tulip-shaped smoothing and pressing-down device made out of a resilient material that applies the blank in the vicinity of the head and neck of the bottle. When the rubber tulip is not subject to stress, its inside diameter is longer than the diameter of the head and neck of the bottle. When the head of the bottle enters the tulip structure, the blank of foil is applied to the head and neck as the walls of the structure stretch. The application of hydraulic pressure to the outside of the tulip structure is unavoidable in order to make the radial force uniform enough to ensure unexceptionable application of the blank to the bottle. Attempts to do without it and to apply and smooth the blank through the expansion of the resilient material alone have not resulted in satisfactory application and such a solution has not turned out to be practical.
Again, smoothing and pressing down the blank with a system of brushes entails the drawbacks that the bottle absolutely must be rotated, that smoothing and brushing on cannot be controlled, and that wear is very high.